SALEM - New plans for a casino complex at Rockingham Park include the return of live thoroughbred racing along with construction of a hotel and a 1,500-seat entertainment complex in addition to gambling tables and slot machines, the project's developer revealed Wednesday night.

The new plan would increase the cost of the project to about $600 million. The proposal for casino gambling now pending in the Legislature would require the company winning a casino license to spend at least $450 million.

Project developer Millenium Gaming unveiled the plans at a public forum in the racetrack's Belmont Room Wednesday night. Millenium holds an option to purchase the track and surrounding property from Rockingham Venture, which has owned the track since the mid 1980s.

While lawmakers consider whether to legalize gambling in the Granite State, the new proposal would not only restore horse racing to Salem, it would also add a convention center, restaurants, a spa, a new track clubhouse and resort features to the proposed casino.

But the plans depend on a casino bill being passed by the Legislature and signed by Gov. Maggie Hassan.

Right now, opponents and supporters of the bill are heading toward a legislative photo finish.

According to state Rep. Robert Elliot, R-Salem, a 45-member legislative committee deliberating a final recommendation on the casino gambling bill, Senate Bill 152, is currently split.

Elliot said 20 members of the panel favor the casino, while 20 are against it.

Five committee members haven't committed one way or the other. The committee is scheduled to meet next week to vote on a final recommendation.

"Once this goes before the entire House, it would take 199 votes for this to pass," Elliot said. "The future of this track could lay in the hands of Salem's nine representatives."

"I hope all of our legislators find this as exciting as I do," park president Ed Callahan said.

Bill Wortman, co-CEO of Millennium said the plans have been a long time in the making. Wortman thanked the citizens of Salem for their 80 percent affirmative vote on a nonbinding casino referendum on the March ballot.

"I think that was a very strong message to send," Wortman said.

Eight years ago, Wortman and his Las Vegas-based gaming company began working towards the ultimate goal of bringing a casino to Salem.

"It was then that I said we were here to stay and we were going to redevelop this project into something you can all be proud of," he told the audience.

Over the years, the vision for The Rock's future has changed with the times.

But the state now finds itself with casinos in Maine and a casino licensing process under way in Massachusetts.

"For this to work in the current marketplace, we need to be competitive but do it in a way that's cohesive to the New Hampshire way of life," Wortman said. "We can't just come in and build a giant, glass building in Salem and expect it to work."

The track's original buildings were designed to accommodate up to 30,000 people. Because of that, infrastructure changes will not be as extensive as they may have been at other potential sites, Wortman noted.

Callahan said a convention center and hotel on the site would fill a void for the area's business community.

"Many of the groups in the area now have to go down to Boston when they host a convention," Callahan said. "So this would serve the needs of the surrounding communities."

The venue would also include a 1,500-seat entertainment facility. Officials believe the theatre venue alone would bring several million people to the area each year.

David Climans, an architect with Climans Green Liang Architects Inc., said he designed the structure as "a destination."

Climans said the new plans, including a refurbished racetrack, give the Salem project a further competitive edge, given the site's lengthy history.

Plans for a new clubhouse at the racetrack draw inspiration from the original Rockingham building that was constructed well over a century ago, he noted. Common motifs of traditional New England architecture with a modern twist would give the site a timeless appearance.

"We want it to look like the buildings were always here," Climans said.

Wortman noted the site plan reconfigures the entire site, with today's racetrack moved to a new area in hopes of fully using the site.

Should the casino bill pass, project officials said it would take around 18 months to complete construction on the new Rockingham, with the construction process expected to bring some 1,300 full-time jobs to the area.

Callahan said the original structure would likely remain open to allow continued operation of charitable gaming during construction.

Methuen, Mass., resident Jerry Valley said he supported the proposal, but was concerned that other New England casinos, such as Foxwoods and Mohegan Sun, would fight the plans.